Studies on the application of enzyme consortia on sugarcane bagasse & production of value-added products

Abstract

Agricultural wastes such as rice straw, sugar beet, and sugarcane bagasse have become a critical environmental issue due to growing agriculture demand. This study aimed to investigate the valorization possibility of sugarcane bagasse waste. For every ton of sugarcane processed, approximately 250-280 kg of bagasse is produced. This study focuses on a biological method to obtain reducing sugar from the SCB by using mold. Aspergillus niger was used to produce enzyme like amylase, cellulase, xylanase and applied them to the SCB to obtain reducing sugar. Later on value-added products like bioethanol, silica powder and activated carbon was produced from the bagasse. Bioethanol is a new and renewable energy source. The second-generation bioethanol production process from lignocellulosic materials has development opportunities. This is because the first generation of bioethanol raw materials is generally a food source. Diversification of raw materials for the bioethanol production process can be developed through the use of non-food or waste sources. Lignocellulosic biomass is considered as the future feedstock for ethanol production because of its low cost and its huge availability. For large-scale biological production of ethanol, it is desirable to use cheaper and more abundant substrates. When producing ethanol from maize or sugarcane the raw material constitutes about 40–70% of the production cost. By using waste products from forestry, agriculture and industry, the costs of the feedstocks be reduced. The residual SCB would be used to synthesis silica from it. Bagasse ash is rich in silica (SiO2), the amount of SiO2 present in the raw sugarcane bagasse ash is 53.10% while the silica composition in acid treatment sample is 88.13%. It is thus an alternative source for silica extraction. In this study, a low-energy and low-chemical consumption method is proposed to obtain silica from bagasse ash using alkali extraction and acid precipitation. A silica yield of 74% were achieved. Activated Carbon (AC) is used for absorbing substances of crystalline form, having a large internal pore structures that make the carbon more suitable absorbent. In this study activated carbon was obtained from the residual SCB after alcohol production and residual ash after silica synthesis. The carbons were activated through chemical activation process using phosphoric acid (H3PO4) as activating agents at room temperature. Iodine value and surface area, Dye removal capacity of the activated carbons produced were investigated. Preparation of activated carbon from sugarcane bagasse is a promising approach to produce cheap and efficient adsorbent for gas pollutants removal. It may be also a solution for the agricultural waste problems in big cities. Methylene Blue adsorption tests suggest that the activated have high adsorption capacity.